Contrast the terms plankton (the organisms that float or drift within the water), nekton (the organisms that swim (powerfully) in the water), and benthos (the organisms on the bottom of a body of water).

Neuston sometimes refers to only that subset of floating organisms that are microscopic[2] or those that rely on surface tension to float.[3] The term pleuston refers to superset including those organisms that float by buoyancy or are macroscopic.